Although eight years have passed since the horrific attack on the World Trade Center, many questions remain unanswered. And too often, attempts to resolve them become highly-politicized.
For instance, where was the plan hatched? Who, exactly, was responsible? Was the CIA negligent in admitting known terrorists into the US? What was the legal framework for President Bush's response? And, most importantly, how can the US prevent terrorist attacks in the future?
In following programs, the world's top thinkers soberly grapple with these formidable questions.